Former Chattanooga Firefighter Marvin Nicholson, Junior is scheduled to go on trial Tuesday for the kidnapping and murder of 15-year-old James Citizen.

Police say Nicholson kidnapped Citizen from the Dodson Avenue area back in October of 2006.

About an hour later people in northern Hamilton County called 911 saying they heard gunshots.

When deputies arrived to investigate they found Citizen's body - he had been shot to death.

Detectives say they think Nicholson abducted and killed Citizen because he thought the teenager broke into his house and stole a gun.

During the pre-trial motions hearing Monday Judge Barry Steelman decided to allow several witnesses and evidence that Nicholson's lawyers did not want at the trial.

One witness is Citizen's sister, who police say told them she saw Nicholson pull up in a car, flash a gun and then order her brother inside before they sped away.

Hamilton County Sheriff's Department Detective Robert Starns testified Monday Citizen's sister was able to pick Nicholson out of four different photo line ups.

An FBI special agent from Pennsylvania, who specializes in cellphone location technology, said Monday the cell tower data he analyzed shows Nicholson, or his cellphone, was in the area of the crime scene when the violence erupted.

It's expected that jury selection will begin Tuesday morning which could allow opening statements to begin later in the day.